[linux.git] / include / net / dst.h

/*
 * net/dst.h	Protocol independent destination cache definitions.
 *
 * Authors:	Alexey Kuznetsov, <[email protected]>
 *
 */

#ifndef _NET_DST_H
#define _NET_DST_H

#include <net/dst_ops.h>
#include <linux/netdevice.h>
#include <linux/rtnetlink.h>
#include <linux/rcupdate.h>
#include <linux/bug.h>
#include <linux/jiffies.h>
#include <net/neighbour.h>
#include <asm/processor.h>

#define DST_GC_MIN	(HZ/10)
#define DST_GC_INC	(HZ/2)
#define DST_GC_MAX	(120*HZ)

/* Each dst_entry has reference count and sits in some parent list(s).
 * When it is removed from parent list, it is "freed" (dst_free).
 * After this it enters dead state (dst->obsolete > 0) and if its refcnt
 * is zero, it can be destroyed immediately, otherwise it is added
 * to gc list and garbage collector periodically checks the refcnt.
 */

struct sk_buff;

struct dst_entry {
	struct rcu_head		rcu_head;
	struct dst_entry	*child;
	struct net_device       *dev;
	struct  dst_ops	        *ops;
	unsigned long		_metrics;
	unsigned long           expires;
	struct dst_entry	*path;
	struct dst_entry	*from;
#ifdef CONFIG_XFRM
	struct xfrm_state	*xfrm;
#else
	void			*__pad1;
#endif
	int			(*input)(struct sk_buff *);
	int			(*output)(struct sk_buff *);

	unsigned short		flags;
#define DST_HOST		0x0001
#define DST_NOXFRM		0x0002
#define DST_NOPOLICY		0x0004
#define DST_NOHASH		0x0008
#define DST_NOCACHE		0x0010
#define DST_NOCOUNT		0x0020
#define DST_FAKE_RTABLE		0x0040
#define DST_XFRM_TUNNEL		0x0080
#define DST_XFRM_QUEUE		0x0100

	unsigned short		pending_confirm;

	short			error;

	/* A non-zero value of dst->obsolete forces by-hand validation
	 * of the route entry.  Positive values are set by the generic
	 * dst layer to indicate that the entry has been forcefully
	 * destroyed.
	 *
	 * Negative values are used by the implementation layer code to
	 * force invocation of the dst_ops->check() method.
	 */
	short			obsolete;
#define DST_OBSOLETE_NONE	0
#define DST_OBSOLETE_DEAD	2
#define DST_OBSOLETE_FORCE_CHK	-1
#define DST_OBSOLETE_KILL	-2
	unsigned short		header_len;	/* more space at head required */
	unsigned short		trailer_len;	/* space to reserve at tail */
#ifdef CONFIG_IP_ROUTE_CLASSID
	__u32			tclassid;
#else
	__u32			__pad2;
#endif

	/*
	 * Align __refcnt to a 64 bytes alignment
	 * (L1_CACHE_SIZE would be too much)
	 */
#ifdef CONFIG_64BIT
	long			__pad_to_align_refcnt[2];
#endif
	/*
	 * __refcnt wants to be on a different cache line from
	 * input/output/ops or performance tanks badly
	 */
	atomic_t		__refcnt;	/* client references	*/
	int			__use;
	unsigned long		lastuse;
	union {
		struct dst_entry	*next;
		struct rtable __rcu	*rt_next;
		struct rt6_info		*rt6_next;
		struct dn_route __rcu	*dn_next;
	};
};

u32 *dst_cow_metrics_generic(struct dst_entry *dst, unsigned long old);
extern const u32 dst_default_metrics[];

#define DST_METRICS_READ_ONLY		0x1UL
#define DST_METRICS_FORCE_OVERWRITE	0x2UL
#define DST_METRICS_FLAGS		0x3UL
#define __DST_METRICS_PTR(Y)	\
	((u32 *)((Y) & ~DST_METRICS_FLAGS))
#define DST_METRICS_PTR(X)	__DST_METRICS_PTR((X)->_metrics)

static inline bool dst_metrics_read_only(const struct dst_entry *dst)
{
	return dst->_metrics & DST_METRICS_READ_ONLY;
}

static inline void dst_metrics_set_force_overwrite(struct dst_entry *dst)
{
	dst->_metrics |= DST_METRICS_FORCE_OVERWRITE;
}

void __dst_destroy_metrics_generic(struct dst_entry *dst, unsigned long old);

static inline void dst_destroy_metrics_generic(struct dst_entry *dst)
{
	unsigned long val = dst->_metrics;
	if (!(val & DST_METRICS_READ_ONLY))
		__dst_destroy_metrics_generic(dst, val);
}

static inline u32 *dst_metrics_write_ptr(struct dst_entry *dst)
{
	unsigned long p = dst->_metrics;

	BUG_ON(!p);

	if (p & DST_METRICS_READ_ONLY)
		return dst->ops->cow_metrics(dst, p);
	return __DST_METRICS_PTR(p);
}

/* This may only be invoked before the entry has reached global
 * visibility.
 */
static inline void dst_init_metrics(struct dst_entry *dst,
				    const u32 *src_metrics,
				    bool read_only)
{
	dst->_metrics = ((unsigned long) src_metrics) |
		(read_only ? DST_METRICS_READ_ONLY : 0);
}

static inline void dst_copy_metrics(struct dst_entry *dest, const struct dst_entry *src)
{
	u32 *dst_metrics = dst_metrics_write_ptr(dest);

	if (dst_metrics) {
		u32 *src_metrics = DST_METRICS_PTR(src);

		memcpy(dst_metrics, src_metrics, RTAX_MAX * sizeof(u32));
	}
}

static inline u32 *dst_metrics_ptr(struct dst_entry *dst)
{
	return DST_METRICS_PTR(dst);
}

static inline u32
dst_metric_raw(const struct dst_entry *dst, const int metric)
{
	u32 *p = DST_METRICS_PTR(dst);

	return p[metric-1];
}

static inline u32
dst_metric(const struct dst_entry *dst, const int metric)
{
	WARN_ON_ONCE(metric == RTAX_HOPLIMIT ||
		     metric == RTAX_ADVMSS ||
		     metric == RTAX_MTU);
	return dst_metric_raw(dst, metric);
}

static inline u32
dst_metric_advmss(const struct dst_entry *dst)
{
	u32 advmss = dst_metric_raw(dst, RTAX_ADVMSS);

	if (!advmss)
		advmss = dst->ops->default_advmss(dst);

	return advmss;
}

static inline void dst_metric_set(struct dst_entry *dst, int metric, u32 val)
{
	u32 *p = dst_metrics_write_ptr(dst);

	if (p)
		p[metric-1] = val;
}

static inline u32
dst_feature(const struct dst_entry *dst, u32 feature)
{
	return dst_metric(dst, RTAX_FEATURES) & feature;
}

static inline u32 dst_mtu(const struct dst_entry *dst)
{
	return dst->ops->mtu(dst);
}

/* RTT metrics are stored in milliseconds for user ABI, but used as jiffies */
static inline unsigned long dst_metric_rtt(const struct dst_entry *dst, int metric)
{
	return msecs_to_jiffies(dst_metric(dst, metric));
}

static inline u32
dst_allfrag(const struct dst_entry *dst)
{
	int ret = dst_feature(dst,  RTAX_FEATURE_ALLFRAG);
	return ret;
}

static inline int
dst_metric_locked(const struct dst_entry *dst, int metric)
{
	return dst_metric(dst, RTAX_LOCK) & (1<<metric);
}

static inline void dst_hold(struct dst_entry *dst)
{
	/*
	 * If your kernel compilation stops here, please check
	 * __pad_to_align_refcnt declaration in struct dst_entry
	 */
	BUILD_BUG_ON(offsetof(struct dst_entry, __refcnt) & 63);
	atomic_inc(&dst->__refcnt);
}

static inline void dst_use(struct dst_entry *dst, unsigned long time)
{
	dst_hold(dst);
	dst->__use++;
	dst->lastuse = time;
}

static inline void dst_use_noref(struct dst_entry *dst, unsigned long time)
{
	dst->__use++;
	dst->lastuse = time;
}

static inline struct dst_entry *dst_clone(struct dst_entry *dst)
{
	if (dst)
		atomic_inc(&dst->__refcnt);
	return dst;
}

void dst_release(struct dst_entry *dst);

static inline void refdst_drop(unsigned long refdst)
{
	if (!(refdst & SKB_DST_NOREF))
		dst_release((struct dst_entry *)(refdst & SKB_DST_PTRMASK));
}

/**
 * skb_dst_drop - drops skb dst
 * @skb: buffer
 *
 * Drops dst reference count if a reference was taken.
 */
static inline void skb_dst_drop(struct sk_buff *skb)
{
	if (skb->_skb_refdst) {
		refdst_drop(skb->_skb_refdst);
		skb->_skb_refdst = 0UL;
	}
}

static inline void skb_dst_copy(struct sk_buff *nskb, const struct sk_buff *oskb)
{
	nskb->_skb_refdst = oskb->_skb_refdst;
	if (!(nskb->_skb_refdst & SKB_DST_NOREF))
		dst_clone(skb_dst(nskb));
}

/**
 * skb_dst_force - makes sure skb dst is refcounted
 * @skb: buffer
 *
 * If dst is not yet refcounted, let's do it
 */
static inline void skb_dst_force(struct sk_buff *skb)
{
	if (skb_dst_is_noref(skb)) {
		WARN_ON(!rcu_read_lock_held());
		skb->_skb_refdst &= ~SKB_DST_NOREF;
		dst_clone(skb_dst(skb));
	}
}


/**
 *	__skb_tunnel_rx - prepare skb for rx reinsert
 *	@skb: buffer
 *	@dev: tunnel device
 *	@net: netns for packet i/o
 *
 *	After decapsulation, packet is going to re-enter (netif_rx()) our stack,
 *	so make some cleanups. (no accounting done)
 */
static inline void __skb_tunnel_rx(struct sk_buff *skb, struct net_device *dev,
				   struct net *net)
{
	skb->dev = dev;

	/*
	 * Clear hash so that we can recalulate the hash for the
	 * encapsulated packet, unless we have already determine the hash
	 * over the L4 4-tuple.
	 */
	skb_clear_hash_if_not_l4(skb);
	skb_set_queue_mapping(skb, 0);
	skb_scrub_packet(skb, !net_eq(net, dev_net(dev)));
}

/**
 *	skb_tunnel_rx - prepare skb for rx reinsert
 *	@skb: buffer
 *	@dev: tunnel device
 *
 *	After decapsulation, packet is going to re-enter (netif_rx()) our stack,
 *	so make some cleanups, and perform accounting.
 *	Note: this accounting is not SMP safe.
 */
static inline void skb_tunnel_rx(struct sk_buff *skb, struct net_device *dev,
				 struct net *net)
{
	/* TODO : stats should be SMP safe */
	dev->stats.rx_packets++;
	dev->stats.rx_bytes += skb->len;
	__skb_tunnel_rx(skb, dev, net);
}

/* Children define the path of the packet through the
 * Linux networking.  Thus, destinations are stackable.
 */

static inline struct dst_entry *skb_dst_pop(struct sk_buff *skb)
{
	struct dst_entry *child = dst_clone(skb_dst(skb)->child);

	skb_dst_drop(skb);
	return child;
}

int dst_discard(struct sk_buff *skb);
void *dst_alloc(struct dst_ops *ops, struct net_device *dev, int initial_ref,
		int initial_obsolete, unsigned short flags);
void __dst_free(struct dst_entry *dst);
struct dst_entry *dst_destroy(struct dst_entry *dst);

static inline void dst_free(struct dst_entry *dst)
{
	if (dst->obsolete > 0)
		return;
	if (!atomic_read(&dst->__refcnt)) {
		dst = dst_destroy(dst);
		if (!dst)
			return;
	}
	__dst_free(dst);
}

static inline void dst_rcu_free(struct rcu_head *head)
{
	struct dst_entry *dst = container_of(head, struct dst_entry, rcu_head);
	dst_free(dst);
}

static inline void dst_confirm(struct dst_entry *dst)
{
	dst->pending_confirm = 1;
}

static inline int dst_neigh_output(struct dst_entry *dst, struct neighbour *n,
				   struct sk_buff *skb)
{
	const struct hh_cache *hh;

	if (dst->pending_confirm) {
		unsigned long now = jiffies;

		dst->pending_confirm = 0;
		/* avoid dirtying neighbour */
		if (n->confirmed != now)
			n->confirmed = now;
	}

	hh = &n->hh;
	if ((n->nud_state & NUD_CONNECTED) && hh->hh_len)
		return neigh_hh_output(hh, skb);
	else
		return n->output(n, skb);
}

static inline struct neighbour *dst_neigh_lookup(const struct dst_entry *dst, const void *daddr)
{
	struct neighbour *n = dst->ops->neigh_lookup(dst, NULL, daddr);
	return IS_ERR(n) ? NULL : n;
}

static inline struct neighbour *dst_neigh_lookup_skb(const struct dst_entry *dst,
						     struct sk_buff *skb)
{
	struct neighbour *n =  dst->ops->neigh_lookup(dst, skb, NULL);
	return IS_ERR(n) ? NULL : n;
}

static inline void dst_link_failure(struct sk_buff *skb)
{
	struct dst_entry *dst = skb_dst(skb);
	if (dst && dst->ops && dst->ops->link_failure)
		dst->ops->link_failure(skb);
}

static inline void dst_set_expires(struct dst_entry *dst, int timeout)
{
	unsigned long expires = jiffies + timeout;

	if (expires == 0)
		expires = 1;

	if (dst->expires == 0 || time_before(expires, dst->expires))
		dst->expires = expires;
}

/* Output packet to network from transport.  */
static inline int dst_output(struct sk_buff *skb)
{
	return skb_dst(skb)->output(skb);
}

/* Input packet from network to transport.  */
static inline int dst_input(struct sk_buff *skb)
{
	return skb_dst(skb)->input(skb);
}

static inline struct dst_entry *dst_check(struct dst_entry *dst, u32 cookie)
{
	if (dst->obsolete)
		dst = dst->ops->check(dst, cookie);
	return dst;
}

void dst_init(void);

/* Flags for xfrm_lookup flags argument. */
enum {
	XFRM_LOOKUP_ICMP = 1 << 0,
};

struct flowi;
#ifndef CONFIG_XFRM
static inline struct dst_entry *xfrm_lookup(struct net *net,
					    struct dst_entry *dst_orig,
					    const struct flowi *fl, struct sock *sk,
					    int flags)
{
	return dst_orig;
} 

static inline struct xfrm_state *dst_xfrm(const struct dst_entry *dst)
{
	return NULL;
}

#else
struct dst_entry *xfrm_lookup(struct net *net, struct dst_entry *dst_orig,
			      const struct flowi *fl, struct sock *sk,
			      int flags);

/* skb attached with this dst needs transformation if dst->xfrm is valid */
static inline struct xfrm_state *dst_xfrm(const struct dst_entry *dst)
{
	return dst->xfrm;
}
#endif

#endif /* _NET_DST_H */
Commit	Line	Data
1da177e4 LT	1	/*
	2	* net/dst.h Protocol independent destination cache definitions.
	3	*
	4	* Authors: Alexey Kuznetsov, <[email protected]>
	5	*
	6	*/
	7
	8	#ifndef _NET_DST_H
	9	#define _NET_DST_H
	10
86393e52	11	#include <net/dst_ops.h>
14c85021	12	#include <linux/netdevice.h>
1da177e4 LT	13	#include <linux/rtnetlink.h>
1da177e4 LT	14	#include <linux/rcupdate.h>
187f1882	15	#include <linux/bug.h>
1da177e4 LT	16	#include <linux/jiffies.h>
	17	#include <net/neighbour.h>
	18	#include <asm/processor.h>
	19
1da177e4 LT	20	#define DST_GC_MIN (HZ/10)
	21	#define DST_GC_INC (HZ/2)
	22	#define DST_GC_MAX (120*HZ)
	23
	24	/* Each dst_entry has reference count and sits in some parent list(s).
	25	* When it is removed from parent list, it is "freed" (dst_free).
	26	* After this it enters dead state (dst->obsolete > 0) and if its refcnt
	27	* is zero, it can be destroyed immediately, otherwise it is added
	28	* to gc list and garbage collector periodically checks the refcnt.
	29	*/
	30
	31	struct sk_buff;
	32
fd2c3ef7	33	struct dst_entry {
1e19e02c	34	struct rcu_head rcu_head;
1da177e4 LT	35	struct dst_entry *child;
1da177e4 LT	36	struct net_device *dev;
62fa8a84 DM	37	struct dst_ops *ops;
62fa8a84 DM	38	unsigned long _metrics;
ecd98837	39	unsigned long expires;
f1dd9c37	40	struct dst_entry *path;
ecd98837	41	struct dst_entry *from;
def8b4fa	42	#ifdef CONFIG_XFRM
1da177e4	43	struct xfrm_state *xfrm;
5635c10d ED	44	#else
5635c10d ED	45	void *__pad1;
def8b4fa	46	#endif
7f95e188 EZ	47	int (input)(struct sk_buff );
7f95e188 EZ	48	int (output)(struct sk_buff );
1da177e4	49
5110effe	50	unsigned short flags;
f6b72b62 DM	51	#define DST_HOST 0x0001
	52	#define DST_NOXFRM 0x0002
	53	#define DST_NOPOLICY 0x0004
	54	#define DST_NOHASH 0x0008
	55	#define DST_NOCACHE 0x0010
	56	#define DST_NOCOUNT 0x0020
e90c1483 HFS	57	#define DST_FAKE_RTABLE 0x0040
	58	#define DST_XFRM_TUNNEL 0x0080
	59	#define DST_XFRM_QUEUE 0x0100
f6b72b62	60
5110effe DM	61	unsigned short pending_confirm;
5110effe DM	62
62fa8a84	63	short error;
f5b0a874 DM	64
	65	/* A non-zero value of dst->obsolete forces by-hand validation
	66	* of the route entry. Positive values are set by the generic
	67	* dst layer to indicate that the entry has been forcefully
	68	* destroyed.
	69	*
	70	* Negative values are used by the implementation layer code to
	71	* force invocation of the dst_ops->check() method.
	72	*/
62fa8a84	73	short obsolete;
f5b0a874 DM	74	#define DST_OBSOLETE_NONE 0
	75	#define DST_OBSOLETE_DEAD 2
	76	#define DST_OBSOLETE_FORCE_CHK -1
ceb33206	77	#define DST_OBSOLETE_KILL -2
62fa8a84 DM	78	unsigned short header_len; /* more space at head required */
62fa8a84 DM	79	unsigned short trailer_len; /* space to reserve at tail */
c7066f70	80	#ifdef CONFIG_IP_ROUTE_CLASSID
f1dd9c37	81	__u32 tclassid;
5635c10d ED	82	#else
5635c10d ED	83	__u32 __pad2;
f1dd9c37 ZY	84	#endif
f1dd9c37 ZY	85
5635c10d ED	86	/*
	87	* Align __refcnt to a 64 bytes alignment
	88	* (L1_CACHE_SIZE would be too much)
	89	*/
	90	#ifdef CONFIG_64BIT
f6b72b62	91	long __pad_to_align_refcnt[2];
5635c10d	92	#endif
f1dd9c37 ZY	93	/*
	94	* __refcnt wants to be on a different cache line from
	95	* input/output/ops or performance tanks badly
	96	*/
1e19e02c ED	97	atomic_t __refcnt; /* client references */
1e19e02c ED	98	int __use;
f1dd9c37	99	unsigned long lastuse;
1e19e02c	100	union {
fc766e4c ED	101	struct dst_entry *next;
	102	struct rtable __rcu *rt_next;
	103	struct rt6_info *rt6_next;
	104	struct dn_route __rcu *dn_next;
1e19e02c	105	};
1da177e4 LT	106	};
1da177e4 LT	107
a4023dd0	108	u32 dst_cow_metrics_generic(struct dst_entry dst, unsigned long old);
a37e6e34	109	extern const u32 dst_default_metrics[];
62fa8a84	110
e5fd387a MK	111	#define DST_METRICS_READ_ONLY 0x1UL
	112	#define DST_METRICS_FORCE_OVERWRITE 0x2UL
	113	#define DST_METRICS_FLAGS 0x3UL
62fa8a84	114	#define __DST_METRICS_PTR(Y) \
e5fd387a	115	((u32 *)((Y) & ~DST_METRICS_FLAGS))
62fa8a84 DM	116	#define DST_METRICS_PTR(X) __DST_METRICS_PTR((X)->_metrics)
	117
	118	static inline bool dst_metrics_read_only(const struct dst_entry *dst)
	119	{
	120	return dst->_metrics & DST_METRICS_READ_ONLY;
	121	}
	122
e5fd387a MK	123	static inline void dst_metrics_set_force_overwrite(struct dst_entry *dst)
	124	{
	125	dst->_metrics \|= DST_METRICS_FORCE_OVERWRITE;
	126	}
	127
a4023dd0	128	void __dst_destroy_metrics_generic(struct dst_entry *dst, unsigned long old);
62fa8a84 DM	129
	130	static inline void dst_destroy_metrics_generic(struct dst_entry *dst)
	131	{
	132	unsigned long val = dst->_metrics;
	133	if (!(val & DST_METRICS_READ_ONLY))
	134	__dst_destroy_metrics_generic(dst, val);
	135	}
	136
	137	static inline u32 dst_metrics_write_ptr(struct dst_entry dst)
	138	{
	139	unsigned long p = dst->_metrics;
	140
1f37070d SH	141	BUG_ON(!p);
1f37070d SH	142
62fa8a84 DM	143	if (p & DST_METRICS_READ_ONLY)
	144	return dst->ops->cow_metrics(dst, p);
	145	return __DST_METRICS_PTR(p);
	146	}
	147
	148	/* This may only be invoked before the entry has reached global
	149	* visibility.
	150	*/
	151	static inline void dst_init_metrics(struct dst_entry *dst,
	152	const u32 *src_metrics,
	153	bool read_only)
	154	{
	155	dst->_metrics = ((unsigned long) src_metrics) \|
	156	(read_only ? DST_METRICS_READ_ONLY : 0);
	157	}
	158
	159	static inline void dst_copy_metrics(struct dst_entry dest, const struct dst_entry src)
	160	{
	161	u32 *dst_metrics = dst_metrics_write_ptr(dest);
	162
	163	if (dst_metrics) {
	164	u32 *src_metrics = DST_METRICS_PTR(src);
	165
	166	memcpy(dst_metrics, src_metrics, RTAX_MAX * sizeof(u32));
	167	}
	168	}
	169
	170	static inline u32 dst_metrics_ptr(struct dst_entry dst)
	171	{
	172	return DST_METRICS_PTR(dst);
	173	}
	174
1da177e4	175	static inline u32
5170ae82	176	dst_metric_raw(const struct dst_entry *dst, const int metric)
1da177e4	177	{
62fa8a84 DM	178	u32 *p = DST_METRICS_PTR(dst);
	179
	180	return p[metric-1];
defb3519 DM	181	}
defb3519 DM	182
5170ae82 DM	183	static inline u32
	184	dst_metric(const struct dst_entry *dst, const int metric)
	185	{
0dbaee3b	186	WARN_ON_ONCE(metric == RTAX_HOPLIMIT \|\|
d33e4553 DM	187	metric == RTAX_ADVMSS \|\|
d33e4553 DM	188	metric == RTAX_MTU);
5170ae82 DM	189	return dst_metric_raw(dst, metric);
	190	}
	191
0dbaee3b DM	192	static inline u32
	193	dst_metric_advmss(const struct dst_entry *dst)
	194	{
	195	u32 advmss = dst_metric_raw(dst, RTAX_ADVMSS);
	196
	197	if (!advmss)
	198	advmss = dst->ops->default_advmss(dst);
	199
	200	return advmss;
	201	}
	202
defb3519 DM	203	static inline void dst_metric_set(struct dst_entry *dst, int metric, u32 val)
defb3519 DM	204	{
62fa8a84	205	u32 *p = dst_metrics_write_ptr(dst);
defb3519	206
62fa8a84 DM	207	if (p)
62fa8a84 DM	208	p[metric-1] = val;
1da177e4 LT	209	}
1da177e4 LT	210
0c3adfb8 GBY	211	static inline u32
	212	dst_feature(const struct dst_entry *dst, u32 feature)
	213	{
bb5b7c11	214	return dst_metric(dst, RTAX_FEATURES) & feature;
0c3adfb8 GBY	215	}
0c3adfb8 GBY	216
1da177e4 LT	217	static inline u32 dst_mtu(const struct dst_entry *dst)
1da177e4 LT	218	{
618f9bc7	219	return dst->ops->mtu(dst);
1da177e4 LT	220	}
1da177e4 LT	221
c1e20f7c SH	222	/* RTT metrics are stored in milliseconds for user ABI, but used as jiffies */
	223	static inline unsigned long dst_metric_rtt(const struct dst_entry *dst, int metric)
	224	{
	225	return msecs_to_jiffies(dst_metric(dst, metric));
	226	}
	227
1da177e4 LT	228	static inline u32
	229	dst_allfrag(const struct dst_entry *dst)
	230	{
0c3adfb8	231	int ret = dst_feature(dst, RTAX_FEATURE_ALLFRAG);
1da177e4 LT	232	return ret;
	233	}
	234
	235	static inline int
d33e4553	236	dst_metric_locked(const struct dst_entry *dst, int metric)
1da177e4 LT	237	{
	238	return dst_metric(dst, RTAX_LOCK) & (1<<metric);
	239	}
	240
7f95e188	241	static inline void dst_hold(struct dst_entry *dst)
1da177e4	242	{
5635c10d ED	243	/*
	244	* If your kernel compilation stops here, please check
	245	* __pad_to_align_refcnt declaration in struct dst_entry
	246	*/
	247	BUILD_BUG_ON(offsetof(struct dst_entry, __refcnt) & 63);
1da177e4 LT	248	atomic_inc(&dst->__refcnt);
	249	}
	250
03f49f34 PE	251	static inline void dst_use(struct dst_entry *dst, unsigned long time)
	252	{
	253	dst_hold(dst);
	254	dst->__use++;
	255	dst->lastuse = time;
	256	}
	257
7fee226a ED	258	static inline void dst_use_noref(struct dst_entry *dst, unsigned long time)
	259	{
	260	dst->__use++;
	261	dst->lastuse = time;
	262	}
	263
7f95e188	264	static inline struct dst_entry dst_clone(struct dst_entry dst)
1da177e4 LT	265	{
	266	if (dst)
	267	atomic_inc(&dst->__refcnt);
	268	return dst;
	269	}
	270
a4023dd0	271	void dst_release(struct dst_entry *dst);
7fee226a ED	272
	273	static inline void refdst_drop(unsigned long refdst)
	274	{
	275	if (!(refdst & SKB_DST_NOREF))
	276	dst_release((struct dst_entry *)(refdst & SKB_DST_PTRMASK));
	277	}
	278
	279	/**
	280	* skb_dst_drop - drops skb dst
	281	* @skb: buffer
	282	*
	283	* Drops dst reference count if a reference was taken.
	284	*/
adf30907 ED	285	static inline void skb_dst_drop(struct sk_buff *skb)
adf30907 ED	286	{
7fee226a ED	287	if (skb->_skb_refdst) {
	288	refdst_drop(skb->_skb_refdst);
	289	skb->_skb_refdst = 0UL;
	290	}
	291	}
	292
	293	static inline void skb_dst_copy(struct sk_buff nskb, const struct sk_buff oskb)
	294	{
	295	nskb->_skb_refdst = oskb->_skb_refdst;
	296	if (!(nskb->_skb_refdst & SKB_DST_NOREF))
	297	dst_clone(skb_dst(nskb));
	298	}
	299
	300	/**
	301	* skb_dst_force - makes sure skb dst is refcounted
	302	* @skb: buffer
	303	*
	304	* If dst is not yet refcounted, let's do it
	305	*/
	306	static inline void skb_dst_force(struct sk_buff *skb)
	307	{
	308	if (skb_dst_is_noref(skb)) {
	309	WARN_ON(!rcu_read_lock_held());
	310	skb->_skb_refdst &= ~SKB_DST_NOREF;
	311	dst_clone(skb_dst(skb));
	312	}
adf30907	313	}
1da177e4	314
d19d56dd	315
290b895e ED	316	/**
	317	* __skb_tunnel_rx - prepare skb for rx reinsert
	318	* @skb: buffer
	319	* @dev: tunnel device
ea23192e	320	* @net: netns for packet i/o
290b895e ED	321	*
	322	* After decapsulation, packet is going to re-enter (netif_rx()) our stack,
	323	* so make some cleanups. (no accounting done)
	324	*/
ea23192e ND	325	static inline void __skb_tunnel_rx(struct sk_buff skb, struct net_device dev,
ea23192e ND	326	struct net *net)
290b895e ED	327	{
290b895e ED	328	skb->dev = dev;
bdeab991 TH	329
bdeab991 TH	330	/*
7539fadc	331	* Clear hash so that we can recalulate the hash for the
bdeab991 TH	332	* encapsulated packet, unless we have already determine the hash
	333	* over the L4 4-tuple.
	334	*/
7539fadc	335	skb_clear_hash_if_not_l4(skb);
290b895e	336	skb_set_queue_mapping(skb, 0);
ea23192e	337	skb_scrub_packet(skb, !net_eq(net, dev_net(dev)));
290b895e ED	338	}
290b895e ED	339
d19d56dd ED	340	/**
	341	* skb_tunnel_rx - prepare skb for rx reinsert
	342	* @skb: buffer
	343	* @dev: tunnel device
	344	*
	345	* After decapsulation, packet is going to re-enter (netif_rx()) our stack,
	346	* so make some cleanups, and perform accounting.
290b895e	347	* Note: this accounting is not SMP safe.
d19d56dd	348	*/
ea23192e ND	349	static inline void skb_tunnel_rx(struct sk_buff skb, struct net_device dev,
ea23192e ND	350	struct net *net)
d19d56dd	351	{
d19d56dd ED	352	/* TODO : stats should be SMP safe */
	353	dev->stats.rx_packets++;
	354	dev->stats.rx_bytes += skb->len;
ea23192e	355	__skb_tunnel_rx(skb, dev, net);
d19d56dd ED	356	}
d19d56dd ED	357
1da177e4 LT	358	/* Children define the path of the packet through the
	359	* Linux networking. Thus, destinations are stackable.
	360	*/
	361
8764ab2c	362	static inline struct dst_entry skb_dst_pop(struct sk_buff skb)
1da177e4	363	{
e433430a	364	struct dst_entry *child = dst_clone(skb_dst(skb)->child);
1da177e4	365
8764ab2c	366	skb_dst_drop(skb);
1da177e4 LT	367	return child;
	368	}
	369
a4023dd0 JP	370	int dst_discard(struct sk_buff *skb);
	371	void dst_alloc(struct dst_ops ops, struct net_device *dev, int initial_ref,
	372	int initial_obsolete, unsigned short flags);
	373	void __dst_free(struct dst_entry *dst);
	374	struct dst_entry dst_destroy(struct dst_entry dst);
1da177e4	375
7f95e188	376	static inline void dst_free(struct dst_entry *dst)
1da177e4	377	{
f5b0a874	378	if (dst->obsolete > 0)
1da177e4 LT	379	return;
	380	if (!atomic_read(&dst->__refcnt)) {
	381	dst = dst_destroy(dst);
	382	if (!dst)
	383	return;
	384	}
	385	__dst_free(dst);
	386	}
	387
	388	static inline void dst_rcu_free(struct rcu_head *head)
	389	{
	390	struct dst_entry *dst = container_of(head, struct dst_entry, rcu_head);
	391	dst_free(dst);
	392	}
	393
	394	static inline void dst_confirm(struct dst_entry *dst)
	395	{
5110effe DM	396	dst->pending_confirm = 1;
5110effe DM	397	}
f2c31e32	398
5110effe DM	399	static inline int dst_neigh_output(struct dst_entry dst, struct neighbour n,
	400	struct sk_buff *skb)
	401	{
425f09ab ED	402	const struct hh_cache *hh;
	403
	404	if (dst->pending_confirm) {
	405	unsigned long now = jiffies;
5110effe	406
5110effe	407	dst->pending_confirm = 0;
425f09ab ED	408	/* avoid dirtying neighbour */
	409	if (n->confirmed != now)
	410	n->confirmed = now;
69cce1d1	411	}
5110effe DM	412
	413	hh = &n->hh;
	414	if ((n->nud_state & NUD_CONNECTED) && hh->hh_len)
	415	return neigh_hh_output(hh, skb);
	416	else
	417	return n->output(n, skb);
1da177e4 LT	418	}
1da177e4 LT	419
d3aaeb38 DM	420	static inline struct neighbour dst_neigh_lookup(const struct dst_entry dst, const void *daddr)
d3aaeb38 DM	421	{
aaa0c23c ZZ	422	struct neighbour *n = dst->ops->neigh_lookup(dst, NULL, daddr);
aaa0c23c ZZ	423	return IS_ERR(n) ? NULL : n;
f894cbf8 DM	424	}
	425
	426	static inline struct neighbour dst_neigh_lookup_skb(const struct dst_entry dst,
	427	struct sk_buff *skb)
	428	{
aaa0c23c ZZ	429	struct neighbour *n = dst->ops->neigh_lookup(dst, skb, NULL);
aaa0c23c ZZ	430	return IS_ERR(n) ? NULL : n;
d3aaeb38 DM	431	}
d3aaeb38 DM	432
1da177e4 LT	433	static inline void dst_link_failure(struct sk_buff *skb)
1da177e4 LT	434	{
adf30907	435	struct dst_entry *dst = skb_dst(skb);
1da177e4 LT	436	if (dst && dst->ops && dst->ops->link_failure)
	437	dst->ops->link_failure(skb);
	438	}
	439
	440	static inline void dst_set_expires(struct dst_entry *dst, int timeout)
	441	{
	442	unsigned long expires = jiffies + timeout;
	443
	444	if (expires == 0)
	445	expires = 1;
	446
	447	if (dst->expires == 0 \|\| time_before(expires, dst->expires))
	448	dst->expires = expires;
	449	}
	450
	451	/* Output packet to network from transport. */
	452	static inline int dst_output(struct sk_buff *skb)
	453	{
adf30907	454	return skb_dst(skb)->output(skb);
1da177e4 LT	455	}
	456
	457	/* Input packet from network to transport. */
	458	static inline int dst_input(struct sk_buff *skb)
	459	{
adf30907	460	return skb_dst(skb)->input(skb);
1da177e4 LT	461	}
	462
	463	static inline struct dst_entry dst_check(struct dst_entry dst, u32 cookie)
	464	{
	465	if (dst->obsolete)
	466	dst = dst->ops->check(dst, cookie);
	467	return dst;
	468	}
	469
a4023dd0	470	void dst_init(void);
1da177e4	471
815f4e57 HX	472	/* Flags for xfrm_lookup flags argument. */
815f4e57 HX	473	enum {
80c0bc9e	474	XFRM_LOOKUP_ICMP = 1 << 0,
815f4e57 HX	475	};
815f4e57 HX	476
1da177e4 LT	477	struct flowi;
1da177e4 LT	478	#ifndef CONFIG_XFRM
452edd59 DM	479	static inline struct dst_entry xfrm_lookup(struct net net,
	480	struct dst_entry *dst_orig,
	481	const struct flowi fl, struct sock sk,
	482	int flags)
1da177e4	483	{
452edd59	484	return dst_orig;
1da177e4	485	}
e87b3998 VY	486
	487	static inline struct xfrm_state dst_xfrm(const struct dst_entry dst)
	488	{
	489	return NULL;
	490	}
	491
1da177e4	492	#else
a4023dd0 JP	493	struct dst_entry xfrm_lookup(struct net net, struct dst_entry *dst_orig,
	494	const struct flowi fl, struct sock sk,
	495	int flags);
e87b3998 VY	496
	497	/* skb attached with this dst needs transformation if dst->xfrm is valid */
	498	static inline struct xfrm_state dst_xfrm(const struct dst_entry dst)
	499	{
	500	return dst->xfrm;
	501	}
1da177e4	502	#endif
1da177e4 LT	503
1da177e4 LT	504	#endif /* _NET_DST_H */